1. Technical Field
The present invention relates to an organic electroluminescent device and a method of manufacturing an organic electroluminescent device.
2. Related Art
Organic electroluminescent devices (hereinafter, referred to as ‘organic EL devices’) have been drawing attention as next-generation display devices. Such an organic EL device is formed by providing an organic EL element, in which a light-emitting layer is interposed between upper and lower electrodes, on a base. Typically, a structure in which an anode, an organic functional layer (hole injection layer, light-emitting layer, and the like) and a cathode are sequentially laminated on a transmissive substrate, such as glass, is adopted for the organic EL device. In addition, the light-emitting layer is caused to emit light by supplying a current to the organic functional layer by means of the anode and the cathode.
It is desirable to improve the luminous efficiency of the organic EL device. Accordingly, JP-A-10-83888 proposes an organic EL device with high brightness and high efficiency in which an organic functional layer is configured to include a hole transporting layer and light-emitting dopants and an electron transporting layer and light-emitting dopants.
However, the organic functional layer is formed by using a vapor deposition method. In the case of a process using such vapor deposition method, for example, if the size of a substrate increases, the workability is decreased. As a result, a manufacturing cost is increased. For this reason, it is demanded to manufacture the organic functional layer, such as a light-emitting layer, by using a liquid phase method, for example, an ink jet method. However, in the case of using an ink jet method, it is difficult to satisfactorily laminate a plurality of light-emitting layers. Accordingly, a problem occurs in that the luminous efficiency of the formed light-emitting layer decreases or the life time of the light-emitting layer becomes short.